Field of the Invention
The present invention relates to a conveyor device with a plurality of transport units which can be conveyed on a conveying track, and a conveyor chain which can be brought into releasable engagement with the transport units for driving the transport units.
Discussion of Related Art
In conveyor systems with chain drives noise emission represents a known problem. Noise is predominantly generated by the knocking and/or dragging of chain links on chain wheels, wherein apart from deflecting movements vibrations of the chain also cause undesirable knocking noises. Due to the metal parts involved colliding with each other, noise levels can become unacceptable, in particular at high conveying speeds. However chains made of metal are still preferred because of their high resistance against wear and their high load-bearing capacity.
Various solutions have therefore been proposed in the art in order to reduce noise levels in conveyor systems with chain drives.
The DE 3101355 C2 describes a roller conveyor consisting of idle rollers rotatably mounted sequentially in a roller conveyor frame and driven, at least partially, by a chain drive, wherein the chain drive consists of sprocket wheels arranged on the idle roller axles of the idle rollers and a drive chain engaging therewith, the drive chain extending within one of the longitudinal beams of the roller conveyor frame, wherein the tensioned span of the drive chain extends within a closed chamber attached to a longitudinal beam. The chamber consists of a sound-absorbing plastic hollow profile, in which the drive chain with its tensioned span is guided. The chamber is limited on all sides by sound-absorbing plastic walls, wherein furthermore guidance of the chain in the hollow profile is ensured. Thus grinding noises on the side walls and knocking noises are prevented in upward direction.